A family of Microsoft word processing software products for creating web, email, and print documents.
I was also very frustrated with this bug and tried most of the suggestions on this page without success.
The problem is not global, but document specific, in some cases paragraph specific! Some paragraphs have the problem some don't. It appeared for me in docs that had been edited by another user on a Mac, resulting in a change to some of the fonts (don't ask me why!)
The solution (at least for me) turned out to be simple. Select all the text in the document and change the font to a standard Word font. (If you have many fonts in the doc by design, you may have to do this paragraph by paragraph.)
Problem gone!